Top environmental negotiators from Japan, the United States and eight other non-European Union industrialized countries will hold secret talks in New Zealand in the middle of February, informed sources said Thursday.

The sources said that the ambassadorial-level officials from the 10 member countries of the so-called Umbrella Group will discuss a joint strategy toward stalled international negotiations on ways to prevent global warming. The group comprises Japan, the U.S., Canada, Australia, New Zealand, Iceland, Norway, Russia, Ukraine and Kazakstan.

The secret meeting of the Umbrella Group in New Zealand will come about three months after the collapse of the sixth Conference of Parties to the United Nations Framework Convention on Climate Change, or COP6, in The Hague.

After marathon all-night negotiations, COP6 collapsed late last month due to sharp differences over details regarding the use of "sinks" and other complex mechanisms for helping industrialized countries reduce carbon dioxide and some other types of greenhouse gases, which are widely blamed for global warming. Sinks are defined as actively managed ecosystems that use forests to absorb carbon dioxide.

COP6 is to be resumed in Bonn in May, but it remains to be seen if some 180 countries will be able to nail down details on those mechanisms.

The U.N. convention was signed at the 1992 Earth Summit in Rio de Janeiro. At COP3 in Kyoto at the end of 1997, the U.N. convention signatory countries adopted the "Kyoto Protocol," which set legally binding targets for industrialized countries to slash the total volume of their greenhouse gas emissions by 5.2 percent from 1990 levels between 2008 and 2012.

The protocol specifically calls for Japan to reduce emissions of carbon dioxide and five other types of greenhouse gases during that period by 6 percent, the U.S. by 7 percent, and the 15-nation European Union by 8 percent.

Although the introduction of the emissions trading and other mechanisms, such as the clean-development mechanism, were agreed upon in principle at COP3, no agreement has so far been reached on the details of the mechanisms because of sharp differences of opinion, even among industrialized countries.

Emissions trading is a concept that is intended to help industrialized countries overcome difficulties in meeting their reduction targets. Those countries will be allowed to purchase the rights to emit greenhouse gases from other industrialized countries that can afford to make deeper cuts than they are obliged by the Kyoto protocol.

Under the clean-development mechanism, industrialized countries will be able to earn "credit" if they provide financial assistance for projects aimed at reducing the emissions of greenhouse gases in developing countries. The credits will be used to help those industrialized countries achieve their gas-reduction targets.

The Umbrella Group countries have pursued a unified strategy against the 15-nation EU in the climate negotiations because they have similar stances on many of the issues that have blocked agreement on the details of sinks and other mechanisms.

For example, Japan and the U.S. insist that the carbon dioxide-absorption effect of forests should be counted as much as possible as domestic efforts to slash greenhouse gas emissions, but the EU objects to the idea. Japan and the U.S. also contend that sinks should be included in the clean-development mechanism, while the EU disagrees.

The issue of emissions trading has also pitted the EU against most other industrialized countries. The EU, backed by many developing countries, calls for imposing strict limits on emissions trading, claiming that unlimited use of the mechanism would discourage industrialized countries from making sufficient efforts at home to cut greenhouse gases.

Although Japan, Germany and many other industrialized countries, not including the U.S., want to see the Kyoto Protocol become effective by 2002 -- one decade after the 1992 Earth Summit -- the collapse of COP6 in The Hague has made that goal more difficult to reach.

The protocol needs to be ratified by 55 signatory countries to the U.N. Framework Convention on Climate Change before it can take effect. But only a dozen developing countries have so far ratified the protocol. No industrialized country has ratified the document because of the lack of agreement on the specifics of the emissions trading and other mechanisms.

The U.S. administration of President-elect George W. Bush is widely believed to hold the key to the future of COP6. But the Bush administration is likely to be much less enthusiastic about COP6 than the current Democratic administration of Bill Clinton.

Bush, who will take office on Jan. 20, has expressed even a skeptical view of the need to get the Kyoto Protocol in place, claiming that there is no solid scientific evidence of greenhouse gases causing global warming.

The Republican-dominated U.S. Congress is also opposed to ratifying the protocol before major developing countries, like China and India, "meaningfully participate" in efforts to cut greenhouse gas emissions.